Vehicle surroundings monitoring devices for notifying the driver of a vehicle of objects existing in the periphery of his/her vehicle have been conventionally used. As technology of this kind, there are those described in Patent Documents 1 to 3, which are noted as sources below.
The object detection device described in Patent Document 1 comprises radar detection means for detecting objects by radar and imaging detection means for detecting objects by imaging. The recognition precision of objects existing in the surroundings of a vehicle is increased by using these means in combination. On the other hand, the recognition precision of the image detection means is worsened when the object exists far away from the vehicle, and in such a case, judgments are therefore made with judgment standards that are more relaxed than when the distance from the vehicle to the object is near.
The image display control device described in Patent Document 2 detects physical objects existing in the periphery of the vehicle, and performs enhanced display according to the risk level. The risk level is determined according to the speed of the vehicle, the distance to the physical object, and the type of physical object.
The vehicle surroundings observation device described in Patent Document 3 is a technique for monitoring the blind spot region from the viewpoint of the driver. This vehicle surroundings observation device comprises live-image capturing means for capturing a live image of the blind spot region in front of the vehicle. A lattice-shaped grid image which shows the depth perception of the road is superimposed and displayed on the live image so that the driver can intuitively ascertain the depth of the live image. When the driver arrives at a position where the blind spot region can be visually observed, the superimposed display of the lattice-shaped grid image is stopped.